South Africa’s state-owned electricity utility Eskom said on Sunday that it may have to impose national load shedding this coming week due to a cracked coal storage silo at its Majuba power station.

The silo, which stores over 10,000 tons of coal, cracked on Saturday afternoon. This affected coal supplies to all six units at the power station. It was generating 1,300 Megawatt (MW) at the time.

“Teams are in the process of dispatching mobile coal feeders to site. In the unlikely event that this contingency is unsuccessful, it may impact the full supply from the power station," Eskom said.

Eskom said load shedding will be used under emergency conditions for limited periods and they have developed three schedules. Stage 1 allows for up to 1,000 MW of the national load to be shed, while Stage 2 allows for up to 2,000 MW of the national load to be shed and Stage 3 allows for up to 4,000 MW of the national load to be shed.

Load shedding will be implemented in most instances in two-hour blocks (with an additional 30 minutes for switching between blocks) during the period 05:00 am to 21:30 pm. The Eskom website currently shows that a Stage 2 load shedding is in place.

Lack of new generating capacity has hampered South Africa’s economic growth over the past few years as Eskom battles to bring new capacity on line. The Medupi power station at Lephalale in the Limpopo province was originally scheduled to connect to the national grid with the first of six 800MW units in 2011, but this is now scheduled for 24 December 2014 with normal commercial operation due in the first quarter 2015.

Eskom in February declared two national power emergencies as forecast peak demand was below available capacity. Current available capacity is of the order of 32,000MW, while peak winter demand is normally above 37,000MW. In 2012 and 2013 Eskom managed that 5,000MW gap by reducing planned maintenance in winter and by buying back power from ferrochrome producers. On 6 March 2014, Eskom implemented the first nation-wide load-shedding since 2008.

The latest system status bulletin showed that capacity available to meet peak demand on 30 October was 31, 293MW, while demand was expected to be 30,952MW or a spare capacity margin of only 341MW or 1%. The international norm is to have a spare capacity margin of 15%. Current planned maintenance on 30 October was 3,364MW, while unplanned outages were 8,752MW.

Statement from the City of Cape Town

The City of Cape Town has been advised by Eskom that they have initiated countrywide load shedding from 8am this morning. This will affect Cape Town residents in both the Eskom supply area and the City supply area. The load shedding schedule for City of Cape Town supply residents is currently at stage 3. Residents and suburbs may be affected at their indicated times, depending on the current demand from Eskom. City load shedding schedules are available at: http://www.capetown.gov.za/en/electricity/Pages/LoadShedding.aspx

Whilst the City is doing everything in its power to assist Eskom for the sake of our residents and businesses, it is important to note that the City is wholly reliant on Eskom for the electricity supply to the entire city. The City is only responsible for electricity distribution in certain parts of the city.

If a customer’s electricity supply remains off for longer than the period specified in the schedules, they should please send an SMS to the City’s technical operations centre on 31220. In certain cases, the restoration of power results in what is known as ‘nuisance tripping’ which often goes unreported due to the assumption that the outage is due to the load shedding.

The City regrets the inconvenience caused, but would like to assure residents that all areas are treated fairly, whether they are supplied by the City or by Eskom. Customers can do their part by switching off all non-essential appliances and by monitoring their usage. Residents are also requested to minimise water usage because in some instances water supply is reliant on electrical pumps. Please note that the constraints on the electricity supply are felt throughout the day during the summer months i.e. there is no ‘evening peak’. As such, responsible consumer practices should please be applied throughout the day.

We will keep Cape Town residents informed as we receive updates from Eskom.